public class J02bianliang {
    public static void main(String[] args) {
        //变量数据范围
        byte b1 = 23;
//        byte b2 = 200;

//        short s1 = 40000;

        //实战中，直接用int即可
        int i1 = 100;
        int num = 30;

        double d1 = 3.14;
        //小数默认就是double
        float money = 300.0f;
        float money2 = 300.0F;


        long l1 = 234;
        long l2 = 2222222222L;
    }
}
